Re: INSERT ... ON CONFLICT {UPDATE | IGNORE}

Heikki Linnakangas <hlinnakangas@vmware.com> wrote:

> INSERT INTO persons (username, real_name, data)
> VALUES('foobar', 'foo bar')
> ON CONFLICT (username), (real_name) IGNORE;

> INSERT INTO persons (username, real_name, data)
> VALUES('foobar', 'foo bar')
> ON CONFLICT (username) IGNORE
> ON CONFLICT (real_name) UPDATE ...;

> INSERT INTO persons (username, real_name, data)
> VALUES('foobar', 'foo bar')
> ON CONFLICT (username, real_name) IGNORE
> ON CONFLICT (real_name) UPDATE username = excluded.username;
> ON CONFLICT (username) UPDATE real_name = excluded.real_name;

I like all of these suggestions, except that I think they reflect a
couple things about the syntax which was never settled[1]. First,
Robert suggested using DUPLICATE instead of CONFLICT, which I think
it clearer. So the above would become:

INSERT INTO persons (username, real_name, data)
VALUES('foobar', 'foo bar')
ON DUPLICATE (username), (real_name) IGNORE;

INSERT INTO persons (username, real_name, data)
VALUES('foobar', 'foo bar')
ON DUPLICATE (username) IGNORE
ON DUPLICATE (real_name) UPDATE ...;

INSERT INTO persons (username, real_name, data)
VALUES('foobar', 'foo bar')
ON DUPLICATE (username, real_name) IGNORE
ON DUPLICATE (real_name) UPDATE username = excluded.username;
ON DUPLICATE (username) UPDATE real_name = excluded.real_name;

Second, he suggested a shorthand way of specifying that all the
values from the failed INSERT should be used for the UPDATE:

INSERT INTO persons (username, real_name, data)
VALUES('foobar', 'foo bar', 'baz')
ON DUPLICATE (username) UPDATE;

I think the first point got lost in the discussion of the second
one.

I don't think either point was ever really settled beyond Robert
and I preferring ON DUPLICATE versus Peter preferring ON CONFLICT.

--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

[1] http://www.postgresql.org/message-id/CA+TgmoZN=2AJKi1n4Jz5BkmYi8r_CPUDW+DtoppmTeLVmsOoqw@mail.gmail.com